This invention relates to novel solid heating fuels. In particular, the present invention involves enhancing the luminosity of the flame obtained from trioxane-based fuel.
Solid or gelled heating fuels have wide potential applications as convenient, easily handled and comparatively safe heat sources. Such solid heating fuels in portable form can be employed in civilian uses such as camping, outdoor cooking of all sort, fire-starting, emergency supplies, and the like. Solid heating fuels are also essential for military use, including the heating of field rations, etc.
A widely accepted form of solid heating fuel is trioxane either formed from a compacted solid powder with or without compaction aids such as magnesium stearate, a pure trioxane melt, or a trioxane melt mixed with an organic binder. Trioxane is a cyclic trimer of formaldehyde. Compacted or melted and then cooled to a solid form, trioxane fuel such as in the shape of pellets is advantageous in view of the lack of toxicity and ease of ignition of this fuel.
An important characteristic of trioxane fuel is its relatively low luminosity. Pure trioxane fuel burns with a clear blue flame. The low luminosity of trioxane fuel is advantageous for military applications such as for field use. However, it can readily be seen that trioxane fuel used as a portable heat source for domestic applications such as for outdoor cooking or for emergency light or heat supplies and the like presents a danger of accidental burning. Consequently, trioxane-based fuel has not found wide use as a domestic energy source.
While many compounds are known to impart luminosity to flames for decoration, such compounds frequently are unsafe or yield toxic combustion products. Thus, it would be advantageous to enhance the luminosity of the flame obtained from trioxane fuel without sacrificing the low toxicity of trioxane fuel. Such a safe and easy to use fuel would increase the desirability of trioxane for domestic applications.
U.S. Pat. No. 4,386,904 discloses a colored flame candle comprising a primary combustible material that burns with a colorless flame including trioxone, a combustion wick and a coloring wick. The combustion wick comprises a cotton yarn to which an oxidation accelerating catalyst such as platinum, palladium, and vanadium is added and the coloring wick which is separated but adjacent to the combustion wick comprises a flammable thread-like material, a metallic color former compound and an oxidation accelerating catalyst as well as a combustible resin coating. As the color forming compound which is carried by the coloring wick the examples are salts of metals such as cobalt, chromium, copper, potassium, sodium, lithium, manganese, antimony, calcium barium, strontium, cesium, rubidium, tin; lower carboxylates such as acetate, hydroxide, nitrate, carbonate; or higher fatty acid salts, such as stearate.
It is a primary object of the present invention to enhance the luminosity of the flame obtained from burning trioxane-based fuel.
A further object of the invention is to enhance the luminosity of the flame obtained from burning trioxane-hased fuel without sacrificing the advantages of trioxane fuels such as the lack of toxicity and ease of ignition.
Still another object of this invention is to enhance the luminosity of the flame obtained from burning trioxane-based fuel so as to render trioxane fuel more safe and thus more desirable for domestic applications.
These and other objects, aspects, and advantages of the invention will be readily apparent to those of ordinary skill in the art on consideration of the following description of the invention.